Instrumented antifriction bearing provided with a sealing device

ABSTRACT

The invention concerns an instrumented antifriction bearing device provided with a non-rotating part comprising a non-rotating ring ( 2 ) and sensing means ( 11 ), a rotating part comprising a rotating ring ( 4 ) and coding means ( 16 ), and at least a row of rolling elements ( 6 ) arranged between the two raceways ( 3, 5 ) of the non-rotating ( 2 ) and the rotating ( 4 ) rings, the sensing means ( 11 ) being fixed in a groove ( 10 ) of said non-rotating ring ( 2 ) arranged proximate to a radial lateral surface ( 2   a ) of the non-rotating ring ( 2 ). The non-rotating part further comprises sealing means ( 21 ) arranged axially between the sensing means ( 11 ) and the rolling elements ( 6 ) substantially at the groove ( 10 ), the sealing means ( 21 ) being separate from the sensing means ( 11 ).

[0001] The present invention relates to the field of instrumentedantifriction bearings equipped with an assembly for detecting rotationparameters such as the angular rotation, the direction of rotation, thespeed and/or the acceleration.

[0002] In a way which is known, for example, from document EPA-0 327434, an instrumented antifriction bearing generally comprises adetection assembly consisting of a sensor secured to the non-rotatingring of the bearing and of an encoder secured to the rotating ring ofthe bearing. The encoder rotates past the sensor in such a way that thesensor generates a signal that represents the rotation parameters of theencoder, for example a sinusoidal or squarewave electrical signal, thefrequency of which is proportional to the rotational speed of theencoder. The encoder may be of multi-pole magnetic or of optical typeand operates in collaboration with a sensor of corresponding type, thatis to say a magneto-sensitive sensor in the case of a magnetic encoderand an optical sensor in the case of an optical encoder. The sensor andthe encoder are arranged on one side of the bearing, each being fixed tothe corresponding ring by means of a support. Each of the supports isfixed by push-fitting onto a cylindrical bearing surface of thecorresponding ring, which is machined for that purpose.

[0003] To prevent the ingress of external contaminants likely to degradethe operation of the detection assembly and the operation of thebearing, seals are provided on each side of said bearing. On theopposite side to the detection assembly, a seal formed of a metal endplate over which a supple portion is overmolded is fixed into an annulargroove in the outer ring. A lip originating from the supple portion rubsagainst a rubbing surface of the inner ring. On the same side as thedetection assembly, a seal also made up of a metal end plate and of asupple portion is fixed to a bore of the sensor support. A liporiginating from the supple portion rubs against a rubbing surface ofthe support of the encoder means.

[0004] The special-purpose machining operations required for fixing theencoder and the sensor which are mounted on their supports are expensiveand relatively bulky.

[0005] Furthermore, in the case of a detection assembly of optical typeit is necessary to avoid the ingress of bearing lubricant between theencoder and the sensor.

[0006] It is an object of the present invention to overcome thedisadvantages of the devices of the prior art.

[0007] It is an object of the present invention to propose aninstrumented antifriction bearing in which the rings are of standardtype designed to be used both with or without detection assembly, andcomprising a seal between the rolling elements and the gap between thesensor and the encoder.

[0008] The instrumented antifriction bearing device according to theinvention is of the type provided with a non-rotating part comprising anon-rotating ring and a sensor means, with a rotating part comprising arotating ring and an encoder means, and with at least one row of rollingelements arranged between two raceways of the non-rotating and rotatingrings, the sensor means being fixed in a groove of the non-rotating ringarranged near a radial lateral face of said non-rotating ring. Thenon-rotating part further comprises a sealing means arranged axiallybetween the sensor means and the rolling elements substantially at thegroove, the sealing means being distinct from the sensor means.

[0009] A seal is thus provided between the sensor means and the rollingelements. The sensor means may be fixed in a standard groove able, inother uses, to accommodate a seal. The encoder means may be fixed to astandard bearing surface of the rotating ring able to collaborate, inother uses, with a seal. It is thus possible to use inexpensive standardrings manufactured and used in great numbers for sealed antifrictionbearings of the “ISO” series, which have no means of measuring rotationparameters. The gap between the encoder and the sensor is effectivelyisolated from the lubricant placed in the bearing.

[0010] An antifriction bearing with information sensor is thus obtainedvery economically from elements of a conventional basic antifrictionbearing, which elements can be chosen from the “ISO” range of thebearing manufacturers.

[0011] Advantageously, the non-rotating ring comprises two groovesarranged one on each side of the rolling elements. The profiles of thetwo grooves may be identical. The non-rotating ring may be symmetricwith respect to a plane passing through the center of the rollingelements.

[0012] Advantageously, the sensor means comprises a support, a part ofwhich is arranged in said groove with the non-rotating ring for thefixing of said sensor means to said non-rotating ring. The part arrangedin said groove may be of a diameter larger than that of the remainder ofthe support. The sensor support here is mounted in the place of aconventional bearing seal.

[0013] In one embodiment of the invention, the sealing means is arrangedradially between a support of the sensor means and the rotating ring.

[0014] Advantageously, the sealing means comprises a substantiallyradial portion of annular shape and an attachment portion in contactwith the sensor means. The attachment portion may collaborate with thesupport of the sensor means. The attachment portion may be mounted withradial gripping on the sensor means.

[0015] In one embodiment of the invention, the attachment portion of thesealing means is also in contact with the non-rotating ring.

[0016] In one embodiment of the invention, the attachment portion of thesealing means comprises a bulge made of supple material. The bulge mayproject into said groove and be in contact both with the support of thesensor means and with the non-rotating ring. The bulge may contribute toholding the support of the sensor means in place.

[0017] In another embodiment of the invention, the attachment portion ofthe sealing means comprises an oblique rim originating from thesubstantially radial portion.

[0018] Advantageously, the sensor means comprises an opening formounting the sealing means, which opening is situated opposite therolling elements and allows said sealing means to be introduced into thesensor means toward the rolling elements.

[0019] Another subject of the present invention is a method ofassembling an instrumented antifriction bearing device. The bearing isof the type provided with a non-rotating part comprising a non-rotatingring and a sensor means, with a rotating part comprising a rotating ringand an encoder means, and with at least one row of rolling elementsarranged between two raceways of the non-rotating and rotating rings, inwhich a sealing means is placed axially between the sensor means and therolling elements, the sealing means being distinct from the sensormeans, the sensor means being fixed in a groove of the non-rotating ringarranged near a radial lateral face of said non-rotating ring, thesealing means being arranged substantially at the groove.

[0020] The sealing means may radially grip the sensor means. The sealingmeans may be mounted via an opening in the sensor means situatedopposite the rolling elements.

[0021] It is possible to mount the support of the sensor means, then thesealing means, then the rest of the sensor means, said support leavingan opening for the passage of the sealing means. These steps of assemblyemploy simple movements which can be performed economically using apress.

[0022] The present invention will be better understood from studying thedetailed description of some embodiments taken by way of non-limitingexamples and illustrated by the appended drawings, in which:

[0023]FIG. 1 is a view in axial section of an antifriction bearingaccording to a first embodiment of the invention;

[0024]FIG. 2 is an enlarged part view of the antifriction bearing ofFIG. 1;

[0025]FIG. 3 is an alternative form of FIG. 2;

[0026]FIG. 4 is a view in axial section of an antifriction bearingaccording to a second embodiment of the invention;

[0027]FIG. 5 is an enlarged part view of the antifriction bearing ofFIG. 4; and

[0028]FIG. 6 is an alternative form of FIG. 5.

[0029] As can be seen in FIGS. 1 and 2, an antifriction bearing 1comprises an outer ring 2 provided with a raceway 3, an inner ring 4provided with a raceway 5, a row of rolling elements 6, in thisinstance, balls, arranged between the raceways 3 and 5, a cage 7 formaintaining the circumferential spacing of the rolling elements 6, and aseal 8 mounted on the outer ring 2 and rubbing on a cylindrical bearingsurface 4 a of the inner ring 4 while at the same time being arrangedradially between said two rings 2 and 4 and axially between the row ofrolling elements 6 and one of the lateral surfaces of said rings 2, 4.The seal 8 is mounted in an annular groove 9 formed in the outer ring 2near its radial lateral surface 2 a. On the opposite side, the outerring 2 is also provided with a groove 10 symmetric with the groove 9with respect to a plane passing through the center of the rollingelements 6.

[0030] The groove 10 comprises a substantially cylindrical surface 10 aadjacent the radial lateral surface 2 a, a concave surface 10 b formingthe bottom of said groove 10, and an oblique surface 10 c situated onthe same side as the rolling elements 6 and meeting the bore 2 b of theouter ring 2.

[0031] A sensor unit referenced 11 in its entirety is mounted on theouter ring 2 on the same side as the groove 10. The sensor unit 11comprises a metal support 12, a metal cap 13 and a sensor element 14embedded in a synthetic central part 15.

[0032] The metal support 12, of annular overall shape, comprises aradial wall 12 a in contact with a radial front surface 2 a of the outerring 2 on the same side as the groove 10 and continued on its internaledge by a substantially tubular rim 12 b in contact with the surface 10a of the groove 10 and the free end 12 c of which is folded radiallyoutward into the groove 10 and attaches the support 12 to the outer ring2. The free end 12 c has a frustoconical shape. The metal support 12also comprises a cylindrical part 12 d extending from the outer edge ofthe radial part 12 a axially away from the bearing 1 and ending in a rim12 e bent obliquely slightly inward. The cylindrical part 12 d isprovided with a notch 12 f.

[0033] The metal cap 12 has the overall shape of a disk with one end oflarge diameter 13 a bent slightly toward the outer ring 2 andcollaborating with the rim 12 e of the cylindrical part 12 d, said rim12 e holding the cap 13 on by gripping around the end 13 a.

[0034] Outside of the region of the notch 12 e, the central part 15 isbounded radially by the cylindrical part 12 d of the support 12 towardthe outside and has a bore 15 a of such a diameter that there is enoughradial space for the encoder, which will be described later on. Thesensor element 14, which is secured to the central part 15, lies flushwith the bore 15 a. One end of the central part 15 projecting radiallyoutward forms a terminal 19 for leading out a wire 20. Said terminal 19passes through the notch 12 e of the cylindrical part 12 d.

[0035] An encoder 16 comprises an annular support 17 and an active part18. The support 17 is of annular shape with T-shaped cross section andcomprises a radial portion 17 a axially in contact with a radial frontsurface 4 b of the inner ring 4 on the same side as the sensor unit 11and a cylindrical portion 17 b extending from the outer edge of theradial portion 17 a axially on both sides, being push-fitted on the sameside as the inner ring 4 onto a cylindrical bearing surface 4 c of saidinner ring 4. The bearing surface 4 c is preferably symmetric with thebearing surface 4 a with respect to a radial plane passing through thecenter of the rolling elements 6.

[0036] The active part 18 of the encoder 16 is of annular shape withgenerally rectangular cross section and arranged on the outer peripheryof the cylindrical portion 17 b. The active part 18 extends axiallytoward the rolling elements 6 beyond the radial portion 17 a between theouter 2 and inner 4 rings, substantially as far as the groove 10 of theouter ring 2.

[0037] The active part 18 extends to close to the bore 15 a of thecentral part 15, with which it forms a radial gap. As the inner ring 4rotates with respect to the outer ring 2, the active part 18 of theencoder 16 rotates past the sensor element 14, which is capable atoutput of supplying an electrical signal. What happens is that theactive part 18 of the encoder 16 is a multi-pole magnetized ring, forexample made of plastoferrite. The encoder 16 and the sensor unit 11form an assembly for detecting rotation parameters.

[0038] The inside diameter of the cap 13 is substantially equal to thediameter of the cylindrical portion 17 b of the support 17 of theencoder 16. A narrow passage creating a seal is formed between the cap13, on the one hand, and the active part 18 and the end of thecylindrical portion 17 b of the support 17 opposite the rolling elements6 on the other. On the same side as the rolling elements 6, thecylindrical portion 17 b of the support 17 extends beyond the activepart 18.

[0039] The bearing 1 also comprises a sealing element 21 of annularshape provided with a radial portion 21 a and with an oblique portion 21b extending outward from the large-diameter free end of the radialportion 21 a. The inside diameter of the sealing element 21 is slightlygreater than the outside diameter of the cylindrical portion 17 b of thesupport 17 of the encoder 16. The sealing element 21 is arranged axiallybetween the active part 18 of the encoder 16 and the cage 7 of therolling elements 6 and radially between the tubular rim 12 b of thesupport 12 of the sensor unit 11 and the cylindrical portion 17 b ofsaid support 17. The free end of the oblique portion 21 b is in contactwith the interior surface of the tubular rim 12 b, on which it pressesradially outward. The sealing element 21 is also in contact via a regionforming a join between the radial portion 21 a and the oblique portion21 b with the surface 10 c of the groove 10 near the bore 2 b.

[0040] Thus, a narrow passage creating a seal is formed radially betweenthe small-diameter end of the radial portion 21 a of the sealing element21 and the cylindrical portion 17 b of the support 17 of the encoder 16,and axially between the radial portion 21 a and the active part 18 ofthe encoder 16. Contact between the sealing element 21 and the obliquesurface 10 c of the groove 10 of the outer ring 2 ensures sealing evenif the rim 12 b and the free end 12 c of the support 12 of the sensorunit 11 are cut into tabs to make them easier to bend toward the surface10 b of the bottom of the groove 10. The oblique portion 21 b of thesealing element 21 has a diameter in the free state which exceeds theinside diameter of the tubular rim 12 b of the support 12. In theassembled state illustrated in FIGS. 1 and 2, said oblique portion 21 bexerts a radially outwardly directed preload on said tubular rim 12 band this tends to strengthen the retention of the support 12 in thegroove 10 of the outer ring 2.

[0041] It may be noted that the sealing element 21, once mounted, issituated axially at the groove 10 of the outer ring and therefore withinthe axial bulk of the bearing, and this constitutes an appreciablefactor in terms of the compactness of the device.

[0042] The sensor-encoder assembly may be assembled as follows. First ofall, the support 12 is placed on the outer ring 2 and the free end 12 cis bent outward, thus retaining it in the groove 10 of the outer ring 2,the free end 12 c being tubular, prior to assembly, after the manner ofthe rim 12 b. With an axial movement, the sealing element 21 isintroduced through the opening consisting of the bore of the rim 12 band said sealing element 21 is moved toward the rolling elements 6, theend of this movement causing the oblique portion 21 b to slide withgripping along the bore of the tubular rim 12 b. The movement is haltedby contact between the sealing element 21 and the oblique surface 10 cof the groove 10 in close proximity to the bore 2 b of the outer ring 2.Next, in a radial movement, the encoder 16 is brought in and its support17 is push-fitted onto the bearing surface 4 c of the inner ring 4.Finally, the central part 15 incorporating the sensor element 14 isarranged in the cylindrical part 12 d of the support 12, then the cap 13is brought in and the end rim 12 e of the cylindrical part 12 d is bentinward and this retains the cap 13 and therefore the central part 15.

[0043] In other words, the sensor unit 11 is designed in such a way thatthe support 12 comprises an opening for mounting of the sealing element21. The opening in this instance is formed by the bore of thecylindrical part 12 d and that of the tubular rim 12 b. The opening hasa radial dimension such that it allows the sealing element 21 to bemounted, preferably in a simple axial movement.

[0044] Furthermore, the inclination of the oblique portion 21 b allowsan axial movement of the sealing element. 21 toward the rollingelements, which allows said element to be mounted on the support 12, butthrough a bracing effect prevents any axial movement of the sealingelement 21 in the opposite direction, thus avoiding an accidentaldisassembly of said element once it has been placed on the support.

[0045] To reduce the axial bulk of the instrumented antifriction bearing1 in its entirety, the central part 15 is provided with an annularprotrusion 15 b extending axially toward the rolling elements 6 andflush with the bore 15 a of said central part 15. The protrusion 15 b isarranged radially between the active part 18 of the encoder 16 on theone hand, and the oblique portion 21 b of the sealing element 21 and thetubular rim 12 b of the support 12 on the other. The protrusion 15 b maybe provided with an oblique outer surface which corresponds in terms ofshape with the oblique portion 12 b of the sealing element 21. Theprotrusion 15 b serves in part to house the sensor element 14, hence areduction in axial bulk. In other words, the protrusion 15 b is arrangedpartly between the two, outer 2 and inner 4, rings, and the sensorelement 14 lies flush with the plane of the radial front surfaces 2 aand 4 a of said outer 2 and inner 4 rings.

[0046] The alternative form illustrated in FIG. 3 is similar to the onedescribed hereinabove except that the sealing element 22 comprises aradial disk 23 of a size that corresponds to the radial portion 21 aillustrated in FIGS. 1 and 2 and arranged substantially at the samepoint in the bearing 1. The sealing element 22 is supplemented by anannular bulge 24, for example made of rubber or elastomer overmoldedonto the outer edge of the disk 23. The outside diameter of the disk 23is smaller than the bore of the tubular rim 12 b of the support 12. Thebulge 24 is arranged, in the mounted state, in contact, on one side,with the oblique surface 10 c of the groove 10 and, on the other side,with the free end 12 c, of frustoconical shape, of the support 12.

[0047] Thus, an excellent seal is obtained between the disk 23 and theouter ring 2. The bulge 24, which is slightly compressed in the mountedstate, exerts a preload on the free end 12 c, and this preload isessentially directed radially outward and tends therefore to reinforcethe retention of said support 12 in the groove 10 of the outer ring 2.The sealing element 22 is mounted by forcibly pushing it into the boreof the tubular rim 12 b of the support 12, the bulge 24 deploying intothe groove 10 at the end of the radial mounting movement.

[0048] In the two alternative forms described hereinabove, it would beentirely possible to provide a sealing lip secured to the sealingelement 21 or 22 and collaborating with the support 17 of the encoder 16or alternatively a sealing lip secured to said support 17 and rubbingagainst the sealing element 21. The axial bulk of the instrumentedantifriction bearing 1 is not altered by the presence of the sealingelement, which is mounted at a similar location to that of aconventional sealed, but uninstrumented, bearing. The sealing elementmakes judicious use of the axial space which in any case is needed forthe attachment of the sensor unit 1 in the groove 10. The sealingelement is of simple shape and constitutes a part distinct from thesensor unit, the various elements of which also have relatively simpleshapes.

[0049] In the embodiment illustrated in FIGS. 4 and 5, the elementswhich are similar to those of the preceding figures bear the samereferences. The sensor unit 11 comprises two parts 25 and 26. The firstpart 25 is attached to the outer ring 2 and supports a light source 27.The second part 26 is attached to the first part 25 and supports anoptical sensor 28. An axial space is provided between the light source27 and the optical sensor 28.

[0050] More specifically, the first part 25 made of synthetic materialcomprises a tubular portion 25 a, a free of which is in contact with theradial surface 2 a of the outer ring 2, and a radial portion 25 bextending inward from the bore of the tubular portion 25 a. The tubularportion 25 a and the radial portion 25 b are annular and aresubstantially T-shaped. The light source 27 lies flush with a radialsurface of the radial portion 25 b on the opposite side to the rollingelements 6. The first part 25 also comprises an attachment portion 25 cextending from the small-diameter end of the radial portion 25 b towardthe rolling elements 6. The attachment portion 25 c has a cylindricaloverall shape and is cut at its free end opposite the radial portion 25b into a number of elastic tabs 29. Each elastic tab 29 is provided witha hook 30 extending radially outward and in contact with the concavesurface 10 b of the groove 10. The tabs 29 also comprise studs 31arranged on their interior surface and the function of which will beexplained below. The studs 31 have a substantially radial surface on thesame side as the rolling elements 6 and an oblique slope on the oppositeside to the rolling elements 6.

[0051] The second part 26 of the sensor unit 11, made of syntheticmaterial, is of annular and radial overall shape and has an axialprotrusion 32, of annular shape, push-fitted into the bore of thetubular portion 25 a of the first part 25 at its opposite end to theradial surface 2 a of the outer ring 2. The optical sensor 28 lies flushwith a radial surface 26 a and is arranged facing the light source 27.The radial surface 26 is arranged near the axial protrusion 32 andsurrounded thereby. The second part 26 also has an axial annular groove26 b adjacent the radial surface 26 a and of smaller diameter.

[0052] The encoder 16 comprises a support 33 and an active part 34,which are formed integrally and made of metal. The support 33 comprisesa radial portion 33 a, in contact with the radial surface 4 b of theinner ring 4 on its interior edge, and an axial protrusion 33 bextending axially toward the rolling elements 6 from the radial portion33 a and push-fitted onto the bearing surface 4 c of the inner ring 4.The support 33 of the encoder 16 also comprises a tubular portion 33 cextending axially away from the rolling elements 6 from thelarge-diameter free end of the radial portion 33 a. The tubular portion33 c has a smaller diameter than the bore of the attachment portion 25 cof the first part 25 of the sensor unit 11 and projects by its free endinto the groove 26 b of the second part 26 of the sensor unit 11 withwhich it forms a narrow passage, ensuring the seal. The active part 34of the encoder 16 is of radial shape running outward from the exteriorsurface of the tubular portion 33 c of the support 33 and is arranged inthe axial space that there is between the light source 27 and theoptical sensor 28. The active part 34 has a smaller diameter than thebore of the protrusion 32 which surrounds it. The active part 34 is cutinto a number of uniformly circumferentially-spaced crenellations 35such that a beam of light emitted by the source 27 passes periodicallybetween the crenellations 35 of the active part 34, the period beinglinked to the speed of relative rotation between the encoder 16 and thesensor unit 11.

[0053] The instrumented antifriction bearing 1 also comprises a sealingelement 36 comprising a metal radial annular disk 37 and a supplecovering 38 secured to the disk 37 and arranged on the radial surface ofsaid disk 37 on the same side as the rolling elements 6 and in closeproximity to its outer edge. The sealing element 36 is arranged axiallybetween the cage 7 and the radial portion 33 a of the support 33 of theencoder 16 and axially between the push-fitting protrusion 33 b of saidsupport 33 and the attachment portion 25 c of the first part 25 of thesensor unit 11.

[0054] More specifically, the covering 38 of the sealing element 36 isin contact with the oblique surface 10 c of the groove 10. The exteriorsurface of the annular disk 37 is in contact with the interior surfaceof the hooks 30 and is held back by the studs 30 against any axialdisassembly movement in a direction away from the rolling elements 6.

[0055] The encoder-sensor assembly is assembled in the same order as theembodiment of FIGS. 1 to 3. First of all, the first part 25 is fixed byarranging the hooks 30 in the groove 10. The sealing element 36 is thenforced axially and slides along the interior surface of the attachmentportion 25 c, past the studs 31, and adopts its definitive positionaxially between the studs 31 and the oblique surface 10 c of the groove10. In this position, the hooks 30 are held in the groove 10, which theycan no longer leave. The encoder 16 is then push-fitted onto the bearingsurface 4 c of the inner ring 4 until the radial portion 33 a of thesupport 33 comes into contact with the radial surface 4 b of the innerring 4. Finally, the second part 26 of the sensor unit 11 is push-fittedinto the bore of the tubular portion 25 a of the first part 25, it beingpossible for the two parts 25 and 26 of the sensor unit to be securedtogether definitively by, for example, ultrasound welding.

[0056] The static seal between the sealing element 36 and the outer ring2 is afforded by the supple elastomer or equivalent covering 38. Thedynamic seal between the sealing element 36 and the rotating part isafforded by the narrow passage formed between the radial disk 37 and, onthe one hand, the push-fitting protrusion 33 b and, on the other hand,the radial portion 33 a of the support 33. The static seal between thesupport 33 and the inner ring is afforded by the push-fitting of theprotrusion 33 b onto the bearing surface 4 c. The dynamic seal betweenthe encoder 16 and the sensor unit 1 is afforded by the narrow passageproduced by the free end of the cylindrical portion 33 c of the support33 projecting into the groove 26 b of the first part 26 of the sensorunit 11.

[0057] Thus, the radial gripping of the disk 37 of the sealing element36 in the annulus of fixing hooks 30 has the effect of strengthening theradial gripping of the hooks 30 in the groove 10 and therefore theretention of the sensor unit 11 in the outer ring 2. The small studs 31projecting inward prevent any disassembly of the sealing element 36 onceit has been fitted. Here, again, the sealing element 36 is fixed in theaxial region of the groove 10 and does not in any way increase the axialbulk of the instrumented bearing 1.

[0058] In the alternative form of FIG. 6, the elements which are similarto those of FIGS. 4 to 5 bear the same references. The sealing element39 comprises a rigid part 40 made of sheet metal, a sealing lip 41overmolded on the interior edge of the rigid part 40 and rubbing againstthe exterior surface of the protrusion 33 b of the support 33 of theencoder 16, thus affording an excellent dynamic seal, and a subtlecovering 42 overmolded on the rigid part 40 and in contact with theoblique surface 10 c of the groove 10. The covering 42 and the sealinglip 41 can be made of elastomer, rubber or of any other equivalentmaterial which affords a static seal in one case and a dynamic seal inthe other.

[0059] The rigid part 40, which is of radial overall shape, is providedon its outer edge with an oblique end 40 a in contact with the interiorsurface 30 a of the annulus of hooks 30. Said interior surface 30 acorresponds in terms of shape with said oblique end 40 a. The dynamicend 40 a is also in contact with the studs 31, preventing disassembly.The free end 40 a is formed in such a way that its slope with respect tothe axis of the bearing 1 tends to prevent disassembly of the first part27 from the sensor unit 11. Thus, during assembly of the sealing element39, the free end 40 a snap-fits beyond the studs 31 and is particularlyeffective at opposing any disassembly movements.

[0060] By virtue of the invention, a compact instrumented antifrictionbearing is produced which is particularly well protected and economicalto manufacture by virtue of the use of standard elements both for theouter ring and for the inner ring of the bearing. The various elementsof the encoder-sensor assembly are mounted using simple axial movements,for example those achieved by means of a press, and this is inexpensive.

1. An instrumented antifriction bearing device of the type provided witha non-rotating part comprising a non-rotating ring (2) and a sensormeans (11), with a rotating part comprising a rotating ring (4) and anencoder means (16), and with at least one row of rolling elements (6)arranged between two raceways of the non-rotating and rotating rings,the sensor means being fixed in a groove (10) of the non-rotating ringarranged near a radial lateral face (2 a) of said non-rotating ring, thenon-rotating part further comprising a sealing means (21) arrangedaxially between the sensor means and the rolling elements substantiallyat the groove (10), the sealing means being distinct from the sensormeans, characterized in that the sealing means is arranged radiallybetween a support of the sensor means and the rotating ring.
 2. Thedevice as claimed in any one of the preceding claims, characterized inthat the sealing means comprises a substantially radial portion (21 a)of annular shape and an attachment portion in contact with the sensormeans.
 3. The device as claimed in claim 2, characterized in that theattachment portion is mounted with radial gripping on the sensor means.4. The device as claimed in claim 2 or 3, characterized in that theattachment portion of the sealing means is also in contact with thenon-rotating ring.
 5. The device as claimed in any one of claims 2 to 4,characterized in that the attachment portion of the sealing meanscomprises a bulge (24) made of supple material.
 6. The device as claimedin any one of claims 2 to 4, characterized in that the attachmentportion of the sealing means comprises an oblique rim (21 b) originatingfrom the substantially radial portion.
 7. The device as claimed in anyone of the preceding claims, characterized in that the sensor meanscomprises an opening for mounting the sealing means, which opening issituated opposite the rolling elements and allows said sealing means tobe introduced into the sensor means toward the rolling elements.
 8. Amethod of assembling an instrumented antifriction bearing device of thetype provided with a non-rotating part comprising a non-rotating ringand a sensor means, with a rotating part comprising a rotating ring andan encoder means, and with at least one row of rolling elements arrangedbetween two raceways of the non-rotating and rotating rings, in which asealing means is placed axially between the sensor means and the rollingelements, the sealing means being distinct from the sensor means, thesensor means being fixed in a groove of the non-rotating ring arrangednear a radial lateral face of said non-rotating ring, the sealing meansbeing arranged substantially at the groove, the sealing means beingarranged radially between a support of the sensor means and the rotatingring.
 9. The method as claimed in claim 9, in which the sealing meansradially grips the sensor means.
 10. The method as claimed in claim 9 or10, in which the sealing means is mounted through an opening in thesensor means situated opposite the rolling elements.